Kolpek, in the IBM Technical Disclosure Bulletin, Vol. 16, No. 2, pp. 391-394, July 1973, describes centering operation upon segments of text within a column in an interactive word processing system. Kolpek required the operator to center the type element, after which the system recorded for playback printing coded keystroke representations of the centering function, backspaces, and the text character segment. Upon the centering mode selection, the system was placed in a non-printing mode wherein the system counted half the number of characters entered and recorded half of the count as backspace control characters. The text stream was recorded in a multiple shift register page memory. Relatedly, Cooper, et al., in U.S. Pat. No. 3,924,723, issued on Dec. 9, 1975, generated a compacted code of centering controls and characters using less memory especially for wide-margined documents. Significantly, both systems required operator centering of the typing element and the control key invocation of the machine determination and recording of text segment widths.
In the co-pending Horn and Shipp application U.S. Ser. No. 305,260, filed on Sept. 24, 1981, entitled "Column Formatting by Typed Example", there is described a multipler text column formatting method executed in an interactive word processing system having a display screen, a keyboard, a memory for storing formatted information, and an intercoupling microprocessor. The method steps include formatting the column widths and gutters, defining a multicolumn table by way of an operator keyed in example line of repeated text and control characters; and vector encoding and saving of the example line in the memory suitable for revision upon recall.
A multi-column table may be conveniently described by a set of width parameters specifying a set of adjacent vertical columns starting at the table left margin and extending to the right margin. "Widths" are defined in terms of the width of a character included within a predetermined font or in absolute escapement units such as 1/1440 inches per unit. A gutter width is a multiple byte number designating the amount of white space in character widths associated with a vertical column. Likewise, a column width is preferably a multiple byte number designating the width of a column text as the number of character units counted relative to the preceding gutter. The first gutter width is specified as a unit count relative to the left margin. Other gutter widths specify unit counts relative to the right edge of the previous column widths.
In Horn, et al type of prompting interactive word processor, multiple text column tables are formatted prior to text entry by invoking a column layout function mode. Consonantly, menued prompts prominently displayed guide the operator to structure the column widths and gutters by repeatedly keying text characters and then spacing over to the next column position and repeatedly keying text characters again defining the width of yet another column. This single entry permits the columns and gutter widths to be automatically aligned with tab stops. The formatted column example line is then vector encoded and saved. If it is subsequently desired to revise a saved table, its encoded format line is recalled, rebuilt, and revised by entering repeated text and control characters to define an altered width of an existing column or a new column. In turn, the revised column example line may be encoded and saved. There is also provided an automatic one character wide gutter insertion when creating a new column to prevent the operator from failing to include a gutter after formatting his adjacent column.